Treesearch

The German Barcode of Life (GBOL) project is a large-scale DNA barcoding initiative to assess the biodiversity of animals, fungi, and plants of Germany. Here we introduce the subproject focusing on rust fungi (Pucciniales, Basidiomycota). This is the only group of fungi represented in the initial 3.5-year phase of the project.

Restoration of forests devastated by nonnative invaders often dominates the attention of forest managers and their actions. However, taking a broader view of the invasion beyond the crisis areas reveals opportunities where proactive management can alter the outcome of the invasion in threatened areas. Proactive management moves past the idea of protecting the hosts from exposure to the established nonnative invader and shifts toward facilitating naturalization by preparing the landscape to sustain critical ecosystem function into the future in the presence of the invader (Schoettle and...

The recent completion of genome sequencing for some rust fungi has contributed to suggest a link between biotrophic specialization and genome size expansion. The measurement of genome sizes for a selection of rust fungi has revealed some of the largest genomes among fungi, with nine rust species with haploid genomes between 300 and 780 Mbp. In particular, Uromyces appendiculatus, Phakopsora pachyrhizi, U. transversalis, and Hemileia vastatrix genomes were measured as 652, 716, 746, and 772 Mbp, respectively. Moreover, flow cytometric analysis of H. vastatrixinfected coffee (Coffea spp.)...

In North America, the nonnative rust fungus Cronartium ribicola kills immature native five-needle pine trees and indirectly predisposes maturing trees to secondary attack by insects and other fungi, which may result in severe mortality. Since the early 1900s when C. ribicola arrived, environmental factors, individual trees, the rust fungus, and insects (for example, mountain pine beetle [Dendroctonus ponderosae]) have all interacted to dramatically change forested ecosystems across North America. To date our white pine blister rust (WPBR) research has generated genomics data from the WPBR...

The health and regeneration of sugar pine (Pinus lambertiana), a major species in the mountain forests of California (USA), has been substantially affected by an exotic pathogen, Cronartium ribicola, which causes white pine blister rust. Seedlings from trees with major gene resistance (MGR) are being used to increase field survival in plantations. Partial resistance (PR) due to multiple genes is considered to be more durable than MGR, providing protection to sugar pines exposed to a virulent form of blister rust.

The core distribution of Rocky Mountain bristlecone pine (Pinus aristata) extends from central Colorado into northern New Mexico with a disjunct population in northern Arizona (USA). Populations are primarily at high elevations and often define the alpine treeline, but the species is also found in open mixed-conifer stands with ponderosa (P. ponderosa) or pinyon (P. edulis) pines. On dry, exposed sites the stands are open and bristlecone is commonly the only species present. The combination of the pine’s adaptive traits with infrequent disturbance has enabled trees on these sites to attain...

Limber pine (Pinus flexilis) is being threatened by the lethal disease white pine blister rust (WPBR) caused by the nonnative pathogen Cronartium ribicola. The types and frequencies of genetic resistance to the rust in native populations before invasion are likely to determine the potential success of restoration or proactive measures.

The nine native species of white pines in the United States (four of which also occur in Canada) are all highly susceptible to white pine blister rust caused by the fungal pathogen Cronartium ribicola. Research and applied programs in the United States and Canada to develop resistant populations of white pine species have been underway for more than 50 years. The regional program based at the U.S. Department of Agriculture Forest Service’s Dorena Genetic Resource Center (DGRC; Cottage Grove, Oregon, USA) has the most experience and continuity and has been active for over 50 years. The DGRC...

Poplar (Populus spp.) leaf rusts caused by Melampsora species are considered among the most crucial sanitary problems threatening poplar stands worldwide. Several major resistance factors specific to poplar rusts have been identified, each of them discovered by using a single Melampsora species. Most of them are inherited from Populus species that did not co-evolve with the pathogen. The origin and function of such “exapted” resistance are thus called into question.

Sugar pine (Pinus lambertiana) and western white pine (Pinus monticola) are two important long-lived conifer species in forests of southwestern Oregon (USA) and elsewhere. Both of these white pine species have been in decline for decades due largely to the presence of the nonnative white pine blister rust, caused by the fungal pathogen Cronartium ribicola. Many land managers are interested in keeping these white pine species present in forest ecosystems or in managed forests, but the very high susceptibility of these species to the blister rust and the lack of information rating the...